Tool chuck



y 1950 w. M. HOFFSOMMER 2,508,459

TOOL CHUCK Filed Aug. 31, 1948 H E N Fl] INVENTOR W175? M A aF/wmws? BY ATTO R N EY Patented May 23, *1 950 =TO0L CHUCK "-waIteiM; Hii'flsommer, Bay'si defN. Y., assignmjtif' Ba'ysiilwaitch 'Io'bl Companyl' Inc., Bayside,

Yg aebrlfor'zition of New York tnpiiucationnugust 31, 1-948, Serial N-o. 47,1129

"particularly use'fulio'r the small "diameter tools used in. line 'i'machine ""Wdrkf and watchmaking, inasmuch ashl'icate "'to'ol's bf this' ftype" frequently become bent "and'the 'phints "or" working portions ""thereofnotc c0ncentrlc "with the axis: the end of the tool willidescribe'za sm'anf diameter circle in J up'eration, land the tool will break iiuring use or will, produce idereuve work.

tool chuck"efiiboilyingimy'invehtion includes means wherebftheT-ehuck fitselfisf'carried by a L ball F and socket mounting." in "the" body of the "device"that "is, the"'po'rti'0n of the assembly v mounted on the drill press spindle; "for example sd that-iby relaiiin'g. a collar or ilockniit' and operciting the 'rd'rill, .pre'ss,'ithe tobli -may' be J-centerd i by simply run'hin'ga; bin or other/guiding means along, the tool to'Ithe end"'thereof' while T'thetool is rotating. .Thej pressure .bf' the; guiding means ionr thelside bf thvtobl v'v ill causeithe' ball to shift l \iv'ithin' the socket arid the' tool tpoint will be coaxial vwith thesbiliille bf the drill press. Thenf the. clambing chllanmay be made home arid the tool'operate'd normally. I

fA-tfeatureso'f my inVe'ntiOn, net found in any tool. ehuckerwmchfr am air/are, is the. provision of means for) resilier'i'tlyflhbldinglthe chuck raj aw -.structurelfir rnly w'vli'thin ftheibody, even whenthe claniioing W cellar isl' loosened, so that the ichuck "jaw and lltherei-ni hbld gtoblwill rotate with! the drill press and .fiillh not return to its original clamping collar Lismadeup. 4 I

,Itvl-is ianc bb'jectiof thee-invention, therefore-- to ..pro'vide anTimprove'd 'tobl "chuck by means cf which the ,poi ntmor Wet-kingc portions (')f r a-= tobl may be madevabsblutelycoastal-with thev spindle ormthe likeif 'the'machine-with which the tool is used.

Other featur es and aldiefitas will hereinafter appear. 7

In the accompanyinghrawings: Fig. 1 is. anyelevation partlylinsection, of one embodiment ci"theinventionfshowing the tool chuck'in centered positiorrianid the clamping col- '=la'r. ..in?: home position;

FigSZds -a i-the clam-pihg collan relaxed o' ne'rmit sin-angular f di'sblacemEnt vef' -the-chuck-' and the there-mew -tained -tool; v

Fig. 3 is== a-pers-pective viewta'i u spring cellar view similar t 1 but shotving 5 for frictionally retaining the chuck in adjustedfito position While the secure-mar eater isrlakd: and

Fig.4 is a side elevatio iii-section, or a second embodiment, the tool"chn'tained therein being in centered position. t

In the accompanyingdrawihgs "It represents one'ernbodiment of my improved to'ol 'chu'ck,""in

which an externally threaded body I [has a'ba'rrfel or sleeve 12 for attachment to thespindle o'r mandrel of a drill press, tapping machine, lathe.

or othermachine. i Thebody if is provided with a preferably conical seat 14 w receive-aspherical head 15 formed with or aifixed to the shank 16 of a chuck H. The chuck itsel'fhas'beenconventionally representedbecauseiperjse, it isin'td- (lental to the invention; "theilliistrat'ed chuck shows the tapered end ,"thre'a.ded barrellfl' with which cooperates" a compre'ssion'conar' gcwh i n serves to clamp the jaws about the shank of the The seat It 'ispre'cisely concentric u' ithfsleete l2, so as to be concentric mmamrwuntm spindle or mandrel of the machine to which the device is afiixed. 1 m

It is to be understood 'thatal'though'the tool 2| has been illustrated as a twist drill, the'r'epi'e sentation is merely typical of any tool'such' as a reamer, tap or lapping tool in which the working end must be concentric with the center of rotation of the'tool or thewo'rk heing o'perated'on.

"The body I! is concentrically counterb'ore'd'to provide a pocket' 22'the base'oj which is preferably slightlybeneath the e'quatqr of the head" 15 (as viewed in Fig. 1). "Withinthispocket 2 21s '35 'ber 24. The-saidspringmernber;see Fig. 3, is preferably a split "ring. I v tightly-preferably press' flttetlseated in the pocket 22. As shown in Fig.1, the spring memmis'alignment, or .zass'umm a new one, before 'the :40

equator, and the'rela ied diaineterof the spring is smaller than that of the 'head' 'l 5 at the latitude 'ofengag'ement with thespring. Hence; since the cup 231s tightly 'held within the pocket 2 2,"the reaction of the spring 24 urges' th'e spherical head 15' upwardly" into frictional contact'with the wall of "the conical seat [4.

' A "Washer 15, prefeiamy having a chaifirerd inner wall for enlarged area engagement wlth the head l5, restsuponthe base ofa screw threaded collar 26. The washer2 5 drites the head" intofla tightly "seated relationship within seat I4 when the collar '26 is made "home,'-ahd it isithe cdoperation of the collar andthefwas'hjer'i 5 which secures the chuck in its 'ultiinate fio'sition.

As is shown in Figsil and"2, the-openingfl through the'base Wall" or the" collar 26 fier'rhits measure of angulardisplacement of theshank 'is'cr thechuck. :"Wmenthecohar'fR is partially unscrewed-s0 that" the Washer 25 has -disengaged from or is in non-confining relationship with the spherical head I5 the resilient pressure exerted in Fig. 2. The importance of the frictional retention of the member 15 in the seat (4 will be appreciated when it is recognized that the drill 1 or other tool is centered by relaxing the collar 26 then operating the drill'press to rotate the. drill; then by means of a smooth rod, pin, or;

. the drill is concentric with the drill spindle. The .mechanic. then stops the. drill press and tightens the collar 26'. If the chuck were hanging free,

4 contact with the wall of said seat to restrain free rotation of said head and therewith associated shank member; a collar disposed about said body and movable axially thereof, said collar having a coaxial opening to accommodate said shank, the diameter of said opening permitting angular movement of said shank relative to said "collar; a bearing surface within said collar and encircling said shank for pressure contact with the surface of said spherical head as the collar is moved axially with respect to said body member; and means for securing said collar with respect to said body to maintain the pressure that is, if the head I5 had been permitted to 1 leave the seat l4, the chuck jaw might not rotate with the body, or centrifugal forces, or the force of gravity, might throw the tool again out of larly numbered, there is employed a resilient Washer 39 preferably disposed within the collar 26 beneath the clamping washer 25. Any bearing washers 3| 'may be utilized to reduce the rubbing friction at the washer 30 as the collar is made. up. So long as collar 26 is not relaxed beyond the limits of expansion of the washer 30, the reaction thereof will cause washer 25 to urge the head [5 into frictional association with the wall of seat l4.

Although the invention has been described by making a fully detailed reference to a certain presently preferred embodiment, such detail of description is tobe understood in an instructive rather than a limiting sense, many changes being possible within the scope of the claims hereto annexed.

said jaw member, said shank having a spherical head portion seatable within said conical seat;

resilient means for urging said spherical head portion into frictional engagement with the wall of said conical seat to restrain free rotative move- .ment of said spherical head and therewith associated shank; a collar member disposed about said body and axially movable relative thereto, said collar member having a concentric opening larger in diameter than the'diameter of said shank to permit the passage of the shank therethrough; and means within said collar member andengageable with the surface of said spherical head for clamping said head tightly in seated position as said collar, member is made home on said body.

2. A-=tool chuck, comprising a body having means of attachment to a machine element, said body having at the end opposite said attachment, a conical seat coaxial with the attachment means; a jaw member for receiving and securing a tool; a shank extending coaxially from said jaw member, said shank having a spherical head seatable within said conical seat; resilientmeans disposed in fixed relation with respect to said body and engageable with the surface of said spherical head for urging the same into frictional exerted on said spherical element.

3. A tool chuck, comprising a body having a barrel extending coaxially therefrom to afford means for attachment to a machine element, said body being externally threaded and having an opening coaxial therewith, said opening being characterized by uniformly convergent side walls; a jaw member for receiving and securing a tool; a shank extending from said jaw member; a hardened member affixed to the end of said shank, said member having a spherical surface tangentially engageable with. the walls of said opening in ball-and-socket relationship therewith; means comprising an elastic body for resiliently maintaining said hardened member in seated position on the walls of said opening; a collar disposed about said body and said shank, said collar being threaded cooperatively with said body; and a bearing member disposed within said collar and engageable with the spherical surface portion of said shank-aifixed member as said collar is secured home on said body to immovably clamp said member against the walls of said body opening.

4. A tool chuck, comprising a body having a barrel extending coaxially therefrom to afford means for attachment to a machine element, said body being externally threaded and having an opening coaxial therewith, said opening being characterized by uniformly convergent side walls; a jaw member for receiving and securing a tool; a shank extending from said jaw member; a

hardened member afiixed to the end of said shank, said member having a spherical surface tangentially engageable with the walls of said opening in'ball-and-socket relationship therewith; means comprising a split ring of spring material maintained in tangential contact with the spherical surface for resiliently maintainingsaid hardened member in seated position on the walls against the walls of said body opening.

WALTER M. HOFFSOMMER.

REFERENCES CITED The following references are ofrecord in the file of this patent: I r

' UNITED STATES PATENTS Number Name Date 3 460,601 Skinner Oct. 6, 1891 821,651 Landgraf May 29, 1906 1,101,601 Wendt June 30, 1914 1,109,625 Cooper Sept. 1, 1914 1,702,810 Buhn Feb. 19, 1929 2,381,102 Boyd Aug. '7, 1945 

